Your issue is not the oil drain, it's the fact that you basically sealed up your engine. I'm blown away you have not been sending dip sticks to the moon every time you start your car lol.
Do not start the car back up like that. If you want to keep your hoses setup the same way, replace your sealed air/oil seperator with a vented catch can (The ones with a filter on top). I prefer running an oem type setup with 2x sealed air/oil seperators.